Conventionally, power-assisted chairs typically include a motor-operated lift mechanism for aiding invalids and those persons requiring assistance in entering or exiting the chair. More particularly, motor-operated lift mechanisms are interconnected between a stationary base assembly and a moveable chair frame. An example of such a power-assisted chair is disclosed in U.S. Pat. No. 4,993,777 to LaPointe.
Some power-assisted chairs also include separate linkage mechanisms for permitting the seat occupant to selectively actuate an extensible leg rest assembly and/or produce reclining angular movement of a seat assembly between “upright” and “reclined” positions. However, many power-assisted chairs which provide such a multi-functional combination require the use of multiple motors for driving (i.e., pushing) the separate linkages which results in extremely large and expensive chair units yet still having limited reclining options. Moreover, such power-assisted chairs typically incorporate a drive mechanism which employs both a power “drive” function (i.e., for extending the leg rest, lifting the chair, and/or reclining the chair) and a power “return” function for returning the chair to the normal seated position.
One power-assisted lift chair that employs a single actuator is disclosed in U.S. Pat. No. 5,730,494 to LaPointe et al. This chair employs a linear actuator with a carrier, wherein the carrier moves rearwardly relative to the base to lift the chair from its upright position. The carrier moves forwardly to move the chair from its upright position to its TV and fully reclined positions.
Those skilled in this art will appreciate that additional chair designs with improved functionality may be desirable.